Filters implemented in integrated circuits may use components known as resonators to generate resonant frequencies. Resonators, however, may experience the problem of spurious responses. A spurious response is any undesirable or unwanted signal on a frequency other than the resonant frequency (e.g., the frequency being broadcast or received). Devices experiencing spurious frequency responses are said to be operating in the spurious mode. A resonator that operates in the spurious mode creates noise and other problems in the overall circuit design of the filter, or any other device that incorporates a resonator.
Resonators may be acoustically coupled such that the electrical signals transmitted through the resonator are transferred acoustically or electromechanically. Resonators may also extend in a lateral fashion, or be horizontally constructed. Often, such horizontal resonators have components, such as electrodes, that are symmetrically structured. Acoustically coupled resonators may also be symmetrical and arranged in a horizontal structure. Acoustically coupled resonators may be implemented in microelectromechanical systems (MEMS) or integrated circuits. Acoustically coupled, horizontal resonators may experience problems such as spurious responses, or operation in the spurious mode.